Boron
New Member
High Solarnerds, have you had bad experiences with MC4 connectors?
I got some recently from Alix - yes dont all jump on me here. It was for the purpose of examining what fake products were like (not for serious use OK).
Looking closely at the basic design, its been carefully formulated originally by authorities (Google it yourself, its way too much for discussion here). Suffice to say that what started out as well intended has IMHO turned out to be a monumental dog's breakfast with serious fire risks associated. This is common knowledge within the installer/ cowboy experts. Unfortunately, for what they are, the original devices are quite expensive ca £5 a pair , whereas the fake products (look identical) are 1/10th of that price. How would a naive customer know the difference. There are many YT vids showing how fires occur with faulty connections - and worse still on a roof where a fault may persist undetected for some time till it results in a dramatic sustained arc/fire one sunnny day and the potential to burn your house down. Some of these connectors maybe hidden and inaccessible beneath roof tiles for example.
In short - there are many manufacturer's in this lucrative trough with only a few who have a credible quality product (I defer to this boards proper rules and do attempt any commercial promotions, however there is a Wiki on the origins of the design https://en.wikipedia.org/wiki/MC4_connector.
My immediate experience resulted in my OP here as I was shocked to learned from an electricians vid about the installations industries dirty secret.
Ignore the first part on how to make an MC4 connection, goto 12:00 where he discusses the issue of connecting all the system components together (also ignore the commercial plug but it pays for an informed opinion IMHO).
In short, dont mix male/female parts from different manufacturers. The vids suggest there may be an ad hoc compatibility chart produced by some brands but will it help you on site?
When connecting your system makers usually present their equipment with a tail and a ready made MC4 connection. Some provide the mating other half for you to use on your own cable (but not always). So you may be faced with cutting off the kit suppliers connector and using a matching MC4 pair. This may invalidate the Kit suppliers warranty - a nasty grey area that should be challenged before buying your kit (eg Solar panels) - ie insist on a full MC4 coupling and preferably the full spec/maker etc in case a spare is needed . If MC4s give trouble they should be immediately cut out and replaced - not just quick fix , uncoupled and refit a few times hoping that will solve the problem - it will almost certainly return. Up to you
When I tried out the fake product, the first thing hit me straight away. The pin and socket were an extremely tight fit, requiring a hammer on my bench to achieve insertion. Then it proved extremely difficult to try and pull them apart. In short, if you made the cable connection (needing some mechanical vice to pull the halves together, then that's it for life. Anything else needs the coupling to be cut out and replaced. Are you happy with that?
IMHO no disconnecting joints should be made at all - ie make off the cables from the panels by cutting off the MC4 and replacing it with a continuous length of cable (with a properly crimped shroud butt joint). Thread the cable down to a ground level junction box and proceed thereafter as you wish (I prefer a crimped butt myself , always leave a loop of spare cable length for any future repairs).
Once inside your Solar shed - up to you - but at least you have ready visible inspection (Power Leccie's switchroom rule - Look Listen Smell).
I got some recently from Alix - yes dont all jump on me here. It was for the purpose of examining what fake products were like (not for serious use OK).
Looking closely at the basic design, its been carefully formulated originally by authorities (Google it yourself, its way too much for discussion here). Suffice to say that what started out as well intended has IMHO turned out to be a monumental dog's breakfast with serious fire risks associated. This is common knowledge within the installer/ cowboy experts. Unfortunately, for what they are, the original devices are quite expensive ca £5 a pair , whereas the fake products (look identical) are 1/10th of that price. How would a naive customer know the difference. There are many YT vids showing how fires occur with faulty connections - and worse still on a roof where a fault may persist undetected for some time till it results in a dramatic sustained arc/fire one sunnny day and the potential to burn your house down. Some of these connectors maybe hidden and inaccessible beneath roof tiles for example.
In short - there are many manufacturer's in this lucrative trough with only a few who have a credible quality product (I defer to this boards proper rules and do attempt any commercial promotions, however there is a Wiki on the origins of the design https://en.wikipedia.org/wiki/MC4_connector.
My immediate experience resulted in my OP here as I was shocked to learned from an electricians vid about the installations industries dirty secret.
In short, dont mix male/female parts from different manufacturers. The vids suggest there may be an ad hoc compatibility chart produced by some brands but will it help you on site?
When connecting your system makers usually present their equipment with a tail and a ready made MC4 connection. Some provide the mating other half for you to use on your own cable (but not always). So you may be faced with cutting off the kit suppliers connector and using a matching MC4 pair. This may invalidate the Kit suppliers warranty - a nasty grey area that should be challenged before buying your kit (eg Solar panels) - ie insist on a full MC4 coupling and preferably the full spec/maker etc in case a spare is needed . If MC4s give trouble they should be immediately cut out and replaced - not just quick fix , uncoupled and refit a few times hoping that will solve the problem - it will almost certainly return. Up to you
When I tried out the fake product, the first thing hit me straight away. The pin and socket were an extremely tight fit, requiring a hammer on my bench to achieve insertion. Then it proved extremely difficult to try and pull them apart. In short, if you made the cable connection (needing some mechanical vice to pull the halves together, then that's it for life. Anything else needs the coupling to be cut out and replaced. Are you happy with that?
IMHO no disconnecting joints should be made at all - ie make off the cables from the panels by cutting off the MC4 and replacing it with a continuous length of cable (with a properly crimped shroud butt joint). Thread the cable down to a ground level junction box and proceed thereafter as you wish (I prefer a crimped butt myself , always leave a loop of spare cable length for any future repairs).
Once inside your Solar shed - up to you - but at least you have ready visible inspection (Power Leccie's switchroom rule - Look Listen Smell).
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